Answer: -9r+3
Explanation:
In order to simplify this expression, all you have to do is combine the like terms. However, because there is an addition and a subtraction sign next to each other, we have to multiply them together to find which sign will stay.
Positive x Positive = Positive
Positive x Negative = Negative <---
Negative x Negative = Positive
Because we know that multiplying a negative sign by a positive sign will give us negative, we have to keep the subtraction sign and remove the addition sign. This leaves us with 4-9r-1. All that is left to do is simplify.
Combine the like terms: 4-1 = 3
Answer: -9r+3
Hope this helps!